Conducting material and a method of fabricating thereof

Abstract

Vias each having no pore are formed in a multilayer ceramic substrate by filling through holes of green sheets with conducting material obtained by: kneading mixed powder particles, adding copper oxide powder particles 50% (in weight) or less to copper powder particles, with a solution including methyl ethyl ketone and 0.5% (in weight) of isosulfonyltridecylbenzene titanate; drying and cracking the kneaded mixed powder particles, producing cracked mixed powder particles; classifying the cracked mixed powder particles with a 100 mesh filter, producing classified mixed powder particles; spheroidizing the classified mixed powder particles with a collision method performed in gases flowing at high speed; and firing the green sheets at a temperature of about 800° C.

What is claimed is: 
     
       1. A multilayer ceramic substrate which packs semiconductor elements in a high density, said multilayer ceramic substrate comprising: a ceramic substrate formed by firing a plurality of stacked green sheets having through holes;   circuit patterns provided on said ceramic substrate; and   a plurality of vias formed in said through holes, for connecting said circuit patterns, by firing a conducting material formed from mixed powder particles, said mixed powder particles being made by mixing spheroidized copper powder particles and spheroidized copper oxide powder particles; each surface of said spheroidized copper powder particles and said spheroidized copper oxide powder particles being coated by an organic titanium compound film, wherein said copper oxide powder particles and said copper powder particles are mixed to form said mixed powder particles so that the weight of said copper oxide powder particles is less than 50% of the weight of said copper powder particles.   
     
     
       2. A multilayer ceramic substrate according to claim 1, wherein said organic titanium compound film is isosulfonyltridecylbenzene titanate. 
     
     
       3. A multilayer ceramic substrate, comprising: a multilayer ceramic substrate body including a plurality of stacked green sheets having a through hole;   circuit patterns formed on said multilayer ceramic substrate body; and   a via formed in said through hole by firing a conducting material formed from mixed powder particles including spheroidized copper powder particles and spheroidized copper oxide powder particles, wherein said copper oxide powder particles and said copper powder particles are mixed to form said mixed powder particles so that the weight of said copper oxide powder particles is less than 50% of the weight of said copper powder particles; each surface of said spheroidized copper powder particles and said spheroidized copper oxide powder particles being coated with isosulfonyltridecylbenzene titanate, said via electrically connecting said circuit patterns.